The invention relates to a fuel injection valve for fuel injection systems of internal combustion engines, in particular for injecting fuel directly into a combustion chamber of an internal combustion engine. Basically, it is possible for the invention to be used both in the case of directly injecting engines and in the case of conventional engines that inject into the induction pipe.
The fuel injection valve according to the invention has a fuel inlet which is designed to allow fuel to flow into the fuel injection valve, and an actuating device which can be electrically activated and cooperates with a valve arrangement in order to discharge fuel into the combustion chamber in a directly or indirectly controlled manner via a fuel outlet. The electromagnetic actuating device in this case has a solenoid arrangement which is to be energized, a substantially magnetically soft magnet yoke arrangement which cooperates therewith, and a substantially magnetically soft magnet armature arrangement which cooperates therewith.
Owing to the continually growing demands of the legislation on exhaust emissions, with limiting values being reduced further, the motor-vehicle internal combustion engine industry is facing the challenge of optimizing the operation of injecting fuel into the combustion chamber in order to optimize the formation of pollutants at their place of origin. Particularly critical are emissions of NOx and particulates. Although it is possible to maintain current limiting values through the development of injection systems with ever higher injection pressures and highly dynamic injectors, and by means of cooled exhaust-gas recirculation and oxidizing converters, it nevertheless appears that the existing measures for reducing emissions have attained their potential. Consequently, variable injection pattern formations are coming to the fore. In this case, the fuel injection rate is varied, either by multiple injection or by selective modulation of the stroke of the Jet needle.